1. Field of the Invention
The present invention relates to aqueous compositions that can be used for cosmetics and to cosmetics containing the same.
2. Description of the Prior Art
Conventionally, a variety of polymer materials have been added to cosmetics for the purpose of increasing or modifying the viscosity of cosmetics and improving the feeling upon application of cosmetics. However, the addition of polymer materials leads to formation of films after drying and thus may cause the problem of a feeling of stiffness, so that it is desired to decrease the used amount of polymer materials.
As viscosity increasing agents capable of alleviating the above-described problems, viscosity increasing agents using semi-synthetic polymers such as cellulose polymers have been reported. These viscosity-increasing agents, however, do not provide a sufficient viscosity increase ratio, and the use of them may result in other problems of insufficient temporal stability and insufficient thixotropy.
On the other hand, it has been reported that the viscosity can be increased by combining a specific quaternary amine polymer (polyquaternium 6, which is classified as a cationic synthetic polyvinyl polymer) and a specific cross-linked starch product. This combination, however, yields an insufficient viscosity increase of about four times and can only be used in a specific pH range (see, e.g., JP2000-514435A (pp. 48-51)).
The present invention was achieved in order to solve the above-described problems, and it is an object of the present invention to provide an aqueous composition that can alleviate, or preferably substantially solve at least one of the problems of the conventional aqueous compositions for cosmetics, i.e., insufficient temporal stability, insufficient viscosity increase, being incapable of being used in a variety of pH ranges and being incapable of providing sufficient thixotropy. More preferably, the aqueous composition of the invention can alleviate all of the above-described problems, and most preferably, it can substantially solve all of the above-described problems. Furthermore, it is an object of the present invention to provide an aqueous composition with superior overall performance that can appropriately adjust the above-described properties.